Ammonia gas has been used in commercial and industrial environments for many years. Some applications for using ammonia are sensitive to contaminants within the ammonia. For example, semiconductor manufacturers use ammonia gas in some of their fabrication processes. Contaminants within the ammonia can adversely affect the quality and quantity of the resulting 1 semiconductor devices. Consequently, semiconductor manufacturers strive to use ammonia gas with the least amount of contamination.
Presently available testing devices and systems require hydrolyzation of the ammonia as one of the steps in testing ammonia gas for contamination. Unfortunately, there are inherent problems associated with the hydrolyzation step that interfere with the goal of detecting contamination. One problem involves the purity of the water used in the process. The water itself must be tested to make sure it has no contaminants. If contaminated water is used, the detected level of contamination of the ammonia may be inaccurate. This extra process of testing the water for contamination is expensive and time consuming. Moreover, if the water is found to contain too many contaminants, the only options are to purify the water or obtain uncontaminated water from another source. Both options involve more expense and time.
Another problem with the hydrolyzation step concerns the loss of some metallic contaminants from the sampled ammonia gas. In hydrolyzation, the ammonia gas bubbles through the water. Contaminants in the ammonia gas are suppose to dissolve into the water. Unfortunately, some of the bubbles of ammonia gas pass through the water before the contaminants can fully dissolve into the water. When the bubbles exit the water and burst, the gas, and any remaining contaminants, are released and vented to an exhaust system. The speed that the bubbles passing through the water and the loss of heat during the hydrolyzation step are major factors in the percentage of contaminants that dissolve in the water. The result is an inaccurate detected level of contamination of the ammonia gas.
Yet another problem with the hydrolyzation step is that water is saturated with ammonia at about 28% which dilutes the sample thus lowering the detection limits of the analysis. Moreover, the dilution process requires that the hydrolyzed liquid be concentrated, which increases the chance for contamination.
There remains a need for an ammonia gas sampling device or system that avoids hydrolyzation.